The present invention relates to a mass-coupling arrangement for a vehicle.
From the prior art it is generally known to drive vehicles solely by means of an electric motor (electric vehicle) or by means of a combination of an electric motor and a drive machine of some other type (hybrid drive). In this context, the electrical energy which is necessary to drive the electric motor is stored in an electrical energy store such as e.g. a battery or an accumulator. The battery can be charged from time to time by means of an external electrical energy source and can serve to store recovered braking energy (recuperation energy).
In known structural configurations of electrically driven vehicles, the battery makes up a disproportionately large portion of the mass compared to the vehicle as a whole. In order to achieve a large range, the electrically driven vehicles are equipped with large batteries which can have a mass of several 100 kg (for example 100 to 400 kg). Therefore, the battery forms up to 30% of the total mass of the vehicle. As a result of the large mass, in the case of an accident the battery constitutes a potential danger. The attachment of the battery to the bodywork of the motor vehicle therefore plays an important role. Known concepts for electrically driven vehicles provide the battery as a uniform rigid block in the region of the underfloor of the vehicle (ideally between the front axle and the rear axle). As a consequence, the battery contributes to lowering the overall center of gravity of the vehicle.
However, it is disadvantageous that in the event of a collision of the vehicle or of an impact of the vehicle large decelerations can occur which, owing to the large mass of the traction batteries, then exert a large shearing force on the vehicle bodywork.
Damping the movement of the vehicle battery in comparison with the rest of the vehicle plays a significant role in the stability behavior of the vehicle in the event of a collision. During a collision—or generally during an unusual deceleration process such as, for example, an emergency braking operation—all the objects with mass of the vehicle or in the interior of the vehicle are subjected to abrupt accelerations which require an acceleration force which is greater the larger the mass of the decelerated object. The time profiles of the acceleration of the individual objects, their respective contribution to the mass, their kinematics and the energetic proportion of the total balance of the kinetic energy are therefore decisive for the time profile of the acceleration of the overall system.
In order to influence the time profile of the acceleration of the overall system favorably in the case of a collision of a vehicle, connecting systems or mass-coupling arrangements between a vehicle battery and the vehicle bodywork are known which temporarily mechanically uncouple the battery, including its carrier structure, from the vehicle bodywork in a controlled fashion. For example, document DE 197 38 620 C1 thus describes a mass-coupling arrangement or a battery-retaining system for vehicle batteries in which all the guide elements at least partially permit a movement of the vehicle battery in the event of an impact. The uncoupling ensures that the mass of the battery passes through its own movement trajectory during the collision of the vehicle, and as a result the acceleration forces acting on the battery are configured in a more favorable way. It is a disadvantage of the specified prior art that the securing force with which the battery is secured in the battery-retaining system is constant and cannot be varied in strength or switched off completely at any time.